It’s easy to play hard in a game that’s close, whether you’re playing from behind or ahead. Fierce competition and a hard fight can bring out the best in us.
But to put that a different way, many players will get lazy when a game isn’t particularly close. They lose hope or give up completely when things look bad. They get overconfident and careless when all seems to be going smoothly. This is a self-destructive quality for a competitive player.
When you’re playing from behind, you need to give yourself every chance to steal a win. When you’re ahead, you need to stay tight and slam the door on the game. If you can come back to win one out of a hundred games that look hopeless, you’ll be a better player for it. Likewise, if you allow one out of every hundred would-be wins to slip away from you, that becomes significant as well.